Method for Driving Information Display Device and Information Display Device Using the Method

ABSTRACT

In an information display device according to the first to third inventions of the present invention, when a particle movement type information display device of passive matrix drive and dynamic drive is driven, the particle movement type information display device configured to be driven by using a drive circuit having an output stage equivalent circuit capable of outputting only two values of a predetermined drive voltage value and ground level (0V). Moreover, in the forth and fifth inventions of the present invention, in the method for driving the information display device, wherein the display media are sealed between two opposed substrates, at least one of which is transparent, and wherein the display media, to which an electrostatic field is applied, are made to move so as to display information such as an image or the like, electrodes of the information display device are connected to predetermined potential in the driving voltage range with low impedance while information refresh (scan) is not performed.

TECHNICAL FIELD

The present invention relates to a method for driving an informationdisplay device, in which a particle movement type information displaydevice of passive matrix drive and dynamic drive is driven, and to theinformation display device capable of driving the particle movement typeinformation display device of passive matrix drive and dynamic drive bymeans of the above-mentioned driving method (the first to thirdinventions).

In addition, the present invention also relates to a method for drivingan information display device, wherein the display media are sealedbetween two opposed substrates, at least one of which is transparent,and wherein the display media, to which an electrostatic field isapplied, are made to move so as to display information such as an imageor the like, and to the information display device using theabove-mentioned method (the forth and fifth inventions).

BACKGROUND ART

As an information display device substitutable for liquid crystaldisplay (LCD), information display devices with the use of technologysuch as an electrophoresis method, an electro-chromic method, a thermalmethod, dichroic-particles-rotary method have been proposed.

These conventional techniques are considered to be useful forinexpensive visual display devices of the next generation compared witha LCD due to merits such as wider field of vision close to normalprinted matter, smaller power consumption or a memory function, andexpected to be spread out to information displays for portable devices,electronic paper and the like. Recently, electrophoresis method formicroencapsulating dispersion liquid made up with dispersion particlesand coloration solution and disposing the liquid between opposedsubstrates, is proposed and expected.

However, in the electrophoresis method, there is a problem that aresponse rate is slow by the reason of viscosity resistance because theparticles migrate among the electrophoresis solution. Further, there isa problem of lacking imaging repetition stability, because particleswith high specific gravity of titanium oxide is scattered withinsolution of low specific gravity and it is difficult to maintain astability of dispersion state. Even in the case of microencapsulating,the cell size is diminished to a microcapsule level in order to make ithard to show the above-mentioned drawbacks, however, an essentialproblem is not overcome at all.

Besides the electrophoresis method using behavior in the solution,recently, a method that electro-conductive particles and a chargetransport layer are installed in a part of the substrate without usingsolution has been proposed. [The Imaging Society of Japan “JapanHardcopy '99” (Jul. 21-23, 1999) Transaction Pages 249-252] However, thestructure becomes complicated because the charge transport layer andfurther a charge generation layer are to be arranged. In addition, it isdifficult to constantly charge the electro-conductive particles, andthus there is a drawback on the lack of stability.

As one method for overcoming the various problems mentioned above, aninformation display device comprising an information display panel isknown, wherein the display media (particles or liquid powders) aresealed between a front substrate provided with a front electrode and aback substrate provided with a back electrode, and wherein the displaymedia, to which an electrostatic field is applied, are made to move bymeans of Coulomb's force so as to display information such as an imageor the like.

(Objects of the First to Third Inventions)

A drive circuit used to drive an information display panel in aninformation display device by passive matrix drive or dynamic drive isrequired to have a drive integrated circuit enable to output polaritydrive voltages respectively to the row and column and a drive integratedcircuit enable to output multi-valued drive voltages respectively to therow and column. However such a drive integrated circuit having afunction of outputting more than one kind of voltages costs high so asto cause an increase in cost.

In addition, it is possible to use a drive integrated circuit with highwithstand voltage instead of a drive integrated circuit having afunction of outputting polarity drive voltages. However such a driveintegrated circuit with high withstand voltage costs high so as to causean increase in cost.

(Objects of the Forth and Fifth Inventions)

FIG. 10 is a block diagram showing an example of a method for driving aconventional information display device. In the example shown in FIG.10, in a display panel 51 panel driving voltage is applied to a terminal52 of the row direction by a row driver 61 while panel driving voltageis applied to a terminal 53 of the column direction by a column driver71. The output stage of the row driver 61 has CMOS structure with twoFETs 62-1 and 62-2, while the output stage of the column driver 71 hasCMOS structure with two FETs 72-2 and 72-2.

In the conventional display panel 51 shown in FIG. 10, every timedisplay image is changed, panel driving voltage is scanned along the rowdirection to rewrite information of an image or the like. When displayimage is not changed, as shown in FIG. 10 two FETs 62-1 and 62-2 of therow driver 61 and two FETs 72-1 and 72-2 of the column driver 71 arekept open state in power-off state. Therefore, the terminal 52 of therow direction and the terminal 53 of the column direction are all OPEN(high impedance) state to stay ready to next rewriting.

The above-mentioned information display device having display memoryproperty usually does not rewrite (scan) the information until thedisplay information is changed (although there are some other ways torewrite the information by regular refresh of the information). In thiscase, if the information is distorted by electrostatic discharge etc,the defect state would be kept for a long time even though the defect isrecovered by the next refresh (scan) of the display information. Inaddition, many of the information display devices selling ultra lowpower consumption have display memory function and is high impedance,therefore, the information such as image etc is easily distorted by tinyenergy such as electrostatic discharge etc.

DISCLOSURE OF INVENTION

An object of the first and second inventions of the present invention isto provide a method for driving an information display device, whereinthe driving voltage is reviewed, a drive circuit arranged with aninexpensive drive integrated circuit is used and cost reduction of theinformation display device is achieved.

An object of the third invention of the present invention is to providea cost reduced information display device by adopting above-mentionedmethod for driving the information display device.

An object of the forth and fifth inventions of the present invention isto eliminate the drawbacks mentioned above, to provide a method fordriving an information display device, in which distortion of displayinformation does not occur during information retention period wheninformation is not refreshed (scanned), and to provide the informationdisplay device using the method.

The method for driving an information display device according to thefirst invention of the present invention is the method for driving aparticle movement type information display device of passive matrixdrive and dynamic drive, characterized in that the particle movementtype information display device is driven by means of a drive circuithaving an output stage equivalent circuit capable of outputting only twovalues of a predetermined driving voltage value and ground level.

In the method for driving the information display device of the firstinvention, it is preferable that a switching operation of writing firstdisplay information and second display information is performed byswitching driving voltage of either row or column which is not scanned.

The method for driving the information display device according to thesecond invention of the present invention is the method for driving aparticle movement type information display device of passive matrixdrive and dynamic drive, characterized in that the particle movementtype information display device is driven by means of a drive circuit inwhich ground level of an output analog circuit can be set independent ofground level of an input digital circuit.

In the method for driving the information display device according tothe second invention, it is preferable that the drive circuit comprisesa drive integrated circuit of triple-well structure or the drive circuitcomprises a floating circuit.

In addition, the information display device according to the thirdinvention of the present invention is characterized in that by means ofthe methods for driving the information display device according to thefirst and second invention, the particle movement type informationdisplay device of passive matrix drive and dynamic drive is driven.

According to the method for driving the information display device ofthe first invention of the above configuration, when the particlemovement type information display device of passive matrix drive anddynamic drive is driven, it is driven by means of a drive circuit havingan output stage equivalent circuit capable of outputting only two valuesof a predetermined driving voltage value and ground level, so that aninexpensive drive circuit using an inexpensive drive circuit forcontrolling the row and column can be used, which is capable ofoutputting only two values of the predetermined driving voltage valueand ground level, instead of an expensive drive integrated circuithaving a function of outputting multi-valued voltages. Therefore, costreduction of the information display device may be possible.

According to the method for driving the information display device ofthe second invention of the above configuration, when the particlemovement type information display device of passive matrix drive anddynamic drive is driven, it is driven by means of a drive circuit inwhich ground level of an output analog circuit can be set independent ofground level of an input digital circuit, so that an inexpensive drivecircuit using an inexpensive drive circuit for controlling the row andcolumn can be used, which has output stage of general C-MOS structurecapable of outputting only unipolarity voltage instead of a driveintegrated circuit capable of outputting polarity voltages. Therefore,cost reduction of the information display device may be possible.

According to the information display device of the third invention ofthe above configuration, it is possible to provide a cost reducedinformation display device since by means of the methods for driving theinformation display device according to the first and second inventionsmentioned above, the particle movement type information display deviceof passive matrix drive and dynamic drive is driven.

The method for driving the information display device according to theforth invention of the present invention is the method for driving theinformation display device, wherein the display media are sealed betweentwo opposed substrates, at least one of which is transparent, andwherein the display media, to which an electrostatic field is applied,are made to move so as to display information such as an image or thelike, characterized in that electrodes of the information display deviceare connected to the predetermined potential in the driving voltagerange with low impedance while information refresh (scan) is notperformed.

As a preferred embodiment of the method for driving the informationdisplay device according to the forth invention of the presentinvention, a circuit for connecting electrodes to predeterminedpotential in a driving voltage range with low impedance is configured tofunction even in power-off state, and a body diode at source-to-drain inoutput stage C-MOS structure of driver is used to set panel drivingpower source to GND level in power-off state so that the electrodes areconnected to GND potential with low impedance.

In addition, the information display device according to the fifthinvention of the present invention is characterized in that theinformation display device is driven by mean of the method for drivingthe information display device according to the forth inventionmentioned above.

According to the forth invention of the present invention, theelectrodes of the information display device are connected to thepredetermined potential in the driving voltage range, preferable to GNDlevel with low impedance while information is not refreshed (scanned),so that the information will not be disturbed even by electrostaticdischarge.

BRIEF DESCRIPTION OF DRAWINGS

[FIG. 1] FIGS. 1 a and 1 b are schematic views respectively showing oneexample of the information display panel used in the information displaydevice according to the invention.

[FIG. 2] FIGS. 2 a and 2 b are schematic views respectively illustratinganother example of the information display panel used in the informationdisplay device according to the invention.

[FIG. 3] FIGS. 3 a and 3 b are schematic views respectively depictingstill another example of the information display panel used in theinformation display device according to the invention.

[FIG. 4] FIGS. 4 a to 4 e are schematic views respectively showing oneexample of the method for driving an information display deviceaccording to the invention in comparison with the prior art.

[FIG. 5] FIG. 5 is a block diagram showing one example of the method fordriving an information display device according to the invention.

[FIG. 6] FIG. 6 is a schematic view showing one example of a shape ofthe partition walls in the information display panel according to theinvention.

[FIG. 7] FIG. 7 is a schematic view showing drive circuit of theinformation display device of the second embodiment according to theinvention.

[FIG. 8] FIGS. 8 a to 8 c are schematic views respectively showingdriving voltages used for drive circuit of the information displaydevice of the second embodiment.

[FIG. 9] FIG. 9 is a schematic view showing drive circuit of theinformation display device of the third embodiment according to theinvention.

[FIG. 10] FIG. 10 is a block diagram showing one example of a method fordriving a conventional information display device.

BEST MODE FOR CARRYING OUT THE INVENTION

At first, a basic construction of an information display panel usingparticles and constituted in an information display device of thepresent invention. In the information display panel used in the presentinvention, an electrostatic field is applied to particles sealed betweentwo opposed substrates. Low-charged particles are attracted to thehigh-charged side and high-charged particles are attracted to thelow-charged side along a direction of the applied electrostatic field bymeans of Coulomb's force, and thus the particles can be movedreciprocally by varying a direction of electrostatic field due to aswitching operation of potential. Accordingly, an image can bedisplayed. Therefore, it is necessary to design the information displaypanel in such a manner that the particles can move evenly and maintainstability during a reciprocal operation or during a reserving state.Here, as to forces applied to the particles, there are an attractionforce between the particles due to Coulomb's force, an imaging forcewith respect to the electrodes or substrates, an intermolecular force, aliquid bonding force, a gravity and the like.

One example of the information display panel used in the invention willbe explained with reference to FIGS. 1 a and 1 b-FIGS. 3 a and 3 b.

In the examples shown in FIGS. 1 a and 1 b, at least two or more groupsof image display media 3 having different optical reflectance andcharging characteristics and consisting of at least one or more groupsof particles (here, a white particle 3W consisting of particles and ablack particle 3B consisting of particles are shown) are moved in aperpendicular direction with respect to substrates 1 and 2, inaccordance with an electric field applied from electrodes (not shown)which are arranged outside of the substrates 1 and 2, so as to display ablack color by viewing the black particle 3B to an observer or so as todisplay a white color by viewing the white particle 3W to the observer.In the example shown in FIG. 1 b, for example grid-like partition walls4 is provided between the substrates 1 and 2 to form a display cell, inaddition to the example shown in FIG. 1 a. Moreover, in FIG. 1 b, thepartition wall arranged at a near side is omitted.

In the examples shown in FIGS. 2 a and 2 b, at least two or more groupsof image display media 3 having different optical reflectance andcharging characteristics and consisting of at least one or more groupsof particles (here, a white particle 3W consisting of particles and ablack particle 3B consisting of particles are shown) are moved in aperpendicular direction with respect to substrates 1 and 2, inaccordance with an electric field generated by applying a voltagebetween an electrode 5 provided with the substrate 1 and an electrode 6provided with the substrate 2, so as to display a black color by viewingthe black particle 3B to an observer or so as to display a white colorby viewing the white particle 3W to the observer. In the example shownin FIG. 2 b, for example grid-like partition walls 4 is provided betweenthe substrates 1 and 2 to form a display cell, in addition to theexample shown in FIG. 2 a. Moreover, in FIG. 2 b, the partition wallarranged at a near side is omitted.

In the examples shown in FIGS. 3 a and 3 b, at least two or more groupsof image display media 3 having different optical reflectance andcharging characteristics and consisting of at least one or more groupsof particles (here a white particle 3W consisting of particles and ablack particle 3B consisting of particles are shown) are moved in aperpendicular direction with respect to substrates 1 and 2, inaccordance with an electric field generated by applying a voltagebetween the electrode 5 provided with the substrate 1 and the electrode6 provided with the substrate 2, so as to display a white color byviewing the white particle 3W to an observer or so as to display a colorof the electrode 6 or the substrate 1 by viewing a color of theelectrode 6 or the substrate 1 to the observer. In the example shown inFIG. 3 b, for example grid-like partition walls 4 is provided betweenthe substrates 1 and 2 to form a display cell, in addition to theexample shown in FIG. 3 a. Moreover, in FIG. 3 b, the partition wallarranged at a near side is omitted.

The above explanations can be applied to a case such that the whiteparticles 3W consisting of particles are substituted by white liquidpowders or a case such that the black particles 3B consisting ofparticles are substituted by black liquid powders.

(Explanation of the First to Third Inventions)

One example of the method for driving an information display deviceaccording to the invention will be explained based on FIGS. 4 a to 4 ein comparison with the prior art. In FIGS. 4 a to 4 e, informationdisplay panels in which information display elements (pixels) arearranged in 3×3 matrix state, are schematically shown for convenience ofexplanation. However electrodes of each rows and columns to applydriving voltage to each pixel are not shown. In the following, examplesthat the method for driving an information display device according tothe present invention is applied to a particle movement type informationdisplay device of passive matrix drive are shown. However, it is alsopossible to apply the method to a particle movement type informationdisplay device of dynamic drive (segment panel).

FIG. 4 a is a view showing a principle of passive matrix drive andillustrating the case that display switching voltage of the informationdisplay panel is 10V. In the case of driving the central pixel in 3×3matrix, −5V is applied to the second row and 5V to the second column, sothat the subtraction of these voltages of 10V (=5V−(−5V)) is applied tothe central pixel. Therefore, the pixel is driven to display thepredetermined image (for example black display). In this case, negativevoltage should be applied to either of row or column.

FIGS. 4 b and 4 c are views respectively showing the prior techniques of“½ bias method” and “−½ bias method” to achieve passive matrix drive. Asshown in these figures, in the case of biasing applied voltage to therow and column as ½ of the drive voltage, negative and positive voltagesamong applied voltages do not occur, so that the applied voltages, whichare completely the same as that in FIG. 4 a become homopolarity.However, in this case two kinds of voltage, not 0V, to the row side inFIG. 4 b and to the column side in FIG. 4 c are necessary simultaneouslyso that “a drive integrated circuit (driver IC) with normal C-MOS outputstage structure capable of outputting only one kind of voltage exceptfor 0V” cannot be used and “an expensive driver IC capable of outputtingtwo or more kinds of voltages” should be used.

In the present invention as shown in FIGS. 4 d and 4 e, two kinds ofvoltages, lower one of which is 0V (ground level), are appliedrespectively to each rows and columns so that “an inexpensive driver ICwith normal C-MOS output stage structure can be used, in which only twokinds of voltages, one is 0V and the other is driving voltage which is5V in writing (for example in switching to black ) and 10V in deleting(for example in switching to white), can be output”. In this case, thelower of two kinds of voltages is 0V, therefore, the absolute value ofcrosstalk is not increased.

When the driving method shown in FIGS. 4 d and 4 e is adopted, twopatterns of disturbed symmetrical property of applied voltage occur anda portion where crosstalk voltage is 0V (a portion free from theinfluence of cross talk) occurs along the row direction in FIG. 4 d andthe column direction in FIG. 4 e. In the case of making a comparisonbetween FIG. 4 d and FIG. 4 e, in FIG. 4 enegative crosstalk voltage(−5V) occurs only in the selected row, therefore, crosstalk occurs forjust a moment during one image forming. The crosstalk voltage is appliedrepeatedly during scanning rows to form one image. However, when theconstitution shown in FIG. 4 e is adopted, crosstalk toward the minusdirection in the figure (for example, crosstalk to turn a pixel thatshould be black into white) occurs only once so as to minimize theinfluence of crosstalk.

In one example of the method for driving an information display deviceaccording to the present invention mentioned above, “an inexpensivedriver IC with general C-MOS output stage structure, in which only twokinds of voltages, one is 0V and the other is driving voltage which is5V in writing (for example in switching to black ) and 10V in deleting(for example in switching to white), can be output” is used to achievecost reduction of the drive circuit. In another example of the methodfor driving an information display device according to the presentinvention, as shown in following embodiments in detail, a drive circuitin which ground level of an analog circuit can be set independent ofground level of a digital circuit, is used so that “an inexpensivedriver IC with general C-MOS output stage structure with low withstandvoltage” is used instead of “an expensive driver IC capable ofoutputting both driving voltage and intermediate voltage” to achievecost reduction of the drive circuit.

According to the method for driving an information display device of thepresent invention, when the information display device is driven, it isdriven by means of a driver IC having an output stage equivalent circuitcapable of outputting only two values of a predetermined drive voltagevalue and ground level, or by means of a drive circuit in which groundlevel of an analog circuit can be set independent of ground level of adigital circuit, so that “an inexpensive driver IC with C-MOS outputstage structure, in which only two kinds of voltages, one is 0V and theother is driving voltage can be output” or “an inexpensive driver ICwith general C-MOS output stage structure with low withstand voltage”can be used to configure the drive circuit and then cost reduction ofthe information display device becomes possible.

Explanation of the Forth and Fifth Inventions)

The characteristics of the method for driving an information displaydevice according to the present invention is that in the informationdisplay device of the above-mentioned configuration, while informationis not refreshed (scanned), electrodes of the information display deviceare connected to predetermined potential in the driving voltage rangewith low impedance. Although any means are available in order to connectthe electrodes to the predetermined potential in the driving voltagerange with low impedance, a circuit explained below is preferably used.

FIG. 5 is a block diagram showing one example of the method for drivingan information display device according to the invention. In the exampleshown in FIG. 5, in a display panel 21 panel driving voltage is appliedto a terminal 22 of the row direction by a row driver 31 while paneldriving voltage is applied to a terminal 23 of the column direction by acolumn driver 41. The output stage of the row driver 31 has CMOSstructure with two FETs 32-1 and 32-2, in which two body diodes 33-1 and33-2 are provided with source-to-drain in C-MOS structure. Similarly,the output stage of the column driver 41 has CMOS structure with twoFETs 42-1 and 42-2, in which two body diodes 43-1 and 43-2 are providedwith source-to-drain in C-MOS structure.

In the example shown in FIG. 5, the panel driving circuit is configuredso that panel driving power source, from which power is supplied to therow driver 31 and the column driver 41, is dropped to GND level inpower-off state. Therefore, even in power-off state, FETs 42-1 and 42-2of the output stage, body diodes 33-1 and 33-2 between source-to-drainof FETs 32-1 and 32-2, or body diodes 43-1 and 43-2 are used to connectthe driver output terminals (i.e. terminals 22 and 23 of the displaypanel 21) to GND level with low impedance.

In this case, low impedance is thought to be valid from the test resultwhen it is not more than 1/10 of impedance of the panel 21. In the caseof the information display device using display media according to thepresent invention, no problems happen during the aerial discharge testup to +/−8 kV when terminals are connected to GND level with no morethan 1M ohm impedance.

Hereinafter, respective members of the information display panelaccording to the invention will be explained in detail.

As for the substrate, at least one of the substrates is the transparentsubstrate 2 through which a color of the particles can be observed fromoutside of the information display panel, and it is preferred to use amaterial having a high transmission factor of visible light and anexcellent heat resistance. The back substrate 1 may be transparent oropaque. Examples of the substrate material include polymer sheets suchas polyethylene terephthalate, polyether sulfone, polyethylene,polycarbonate, polyimide or acryl and metal sheets having flexibilityand inorganic sheets such as glass, quartz or the like having noflexibility. The thickness of the substrate is preferably 2 to 5000 μm,more preferably 5 to 2000 μm. When the thickness is too thin, it becomesdifficult to maintain strength and distance uniformity between thesubstrates, and when the thickness is thicker than 5000 μm, it isinconvenient for the thin information display panel.

When electrodes are provided with the information display panel, asmaterials for forming the electrodes , metals such as aluminum, silver,nickel, copper, gold and so on, conductive metal oxides such as ITO,indium oxide, conductive tin oxide and conductive zinc oxide and so on,and conductive polymer such as polyaniline, polypyrrole, polythiopheneand so on are listed and appropriately used. As the method for formingthe electrode, the method in which a thin film is formed from theabove-listed materials by sputtering method, vacuum vapor depositionmethod, CVD (chemical vapor deposition) method, and coating method, orthe method in which the mixed solution of an conductive agent with asolvent or a synthetic resin binder is applied, are used. The electrodedisposed on the substrate at the observation side (display side) shouldbe transparent but the electrode disposed on the back substrate may notbe transparent. In both cased, above-mentioned conductive materialcapable of pattern forming can be preferably used. Additionally, thethickness of the electrode is preferable to be 3 to 1000 nm, morepreferable to be 5 to 400 nm so that the electro-conductivity andoptical transparency can be maintained. The material and the thicknessof the electrode arranged on the back substrate are the same as those ofthe electrode arranged at the display side, but transparency is notnecessary. In this case, the applied outer voltage may be superimposedwith a direct current or an alternate current.

As for the partition wall 4 provided if necessary, a shape of thepartition wall is suitably designed in accordance with a kind of thedisplay media used for the display and is not restricted. However, it ispreferred to set a width of the partition wall to 2-100 μm morepreferably 3-50 μm and to set a height of the partition wall to 10-500μm more preferably 10-200 μm. Moreover, there are a double rib methodand single rib method as a method of forming the partition wall. In thedouble rib method ribs are formed on the opposed substrates respectivelyand then connected with each other. In the single rib method a rib isformed on one of the opposed substrates only. Both methods mentionedabove may be preferably applied to the present invention.

The cell formed by the partition walls each made of rib has a squareshape, a triangular shape, a line shape, a circular shape and a hexagonshape, and has an arrangement such as a grid, a honeycomb and a mesh, asshown in FIG. 6 viewed from a plane surface of the substrate. It ispreferred that the portion corresponding to a cross section of thepartition wall observed from the display side (an area of the frameportion of the display cell) should be made as small as possible, sothat sharpness of the image display can be improved. As the formationmethod of the partition wall there are a die transferring method, ascreen-printing method, a sandblast method, a photolithography methodand an additive method. Among them, it is preferred to use aphotolithography method using a resist film and a die transferringmethod.

Next, the particles used for the display media in the informationdisplay panel according to the invention will be explained. A particleconstituting the particles, which is mainly formed by resin can contain,if necessary, charge control agent, coloring agent, inorganic additiveand the like same as a conventional particle. Hereinafter, resin,contain charge control agent, coloring agent and other additive will belisted.

Typical examples of the resin include urethane resin, urea resin,acrylic resin, polyester resin, acryl urethane resin, acryl urethanesilicone resin, acryl urethane fluorocarbon polymers, acryl fluorocarbonpolymers, silicone resin, acryl silicone resin, epoxy resin, polystyreneresin, styrene acrylic resin, polyolefin resin, butyral resin,vinylidene chloride resin, melamine resin, phenolic resin, fluorocarbonpolymers, polycarbonate resin, polysulfon resin, polyether resin, andpolyamide resin. Two kinds or more of these may be mixed and used. Forthe purpose of controlling the adherence to the substrate, acrylurethane resin, acryl silicone resin, acryl fluorocarbon polymers, acrylurethane silicone resin, acryl urethane fluorocarbon polymers,fluorocarbon polymers, silicone resin are particularly preferable.

Though charge control agents are not particularly specified to thefollowing examples, examples of the negative charge control agentinclude salicylic acid metal complex, metal containing azo dye,oil-soluble dye of metal-containing (containing a metal ion or a metalatom), the fourth grade ammonium salt-based compound, calixarenecompound, boron-containing compound (benzyl acid boron complex), andnitroimidazole derivative. Examples of the positive charge control agentinclude nigrosine dye, triphenylmethane compound, the fourth gradeammonium salt-based compound, polyamine resin, imidazole derivatives.Additionally, metal oxides such as ultra-fine particles of silica,ultra-fine particles of titanium oxide, ultra-fine particles of alumina,and so on; nitrogen-containing circular compound such as pyridine, andso on, and these derivates or salts; and resins containing variousorganic pigments, fluorine, chlorine, nitrogen and the like can beemployed as the charge control agent.

As for a coloring agent, various kinds of organic or inorganic pigmentsor dye with various colors as described below are usable.

Examples of black pigments include carbon black, copper oxide, manganesedioxide, aniline black, activate carbon and the like.

Examples of blue pigments include C.I. pigment blue 15:3, C.I. pigmentblue 15, Berlin blue, cobalt blue, alkali blue lake, Victoria blue lake,phthalocyanine blue, metal-free phthalocyanine blue, partiallychlorinated phthalocyanine blue, first sky blue, Indanthrene blue BC andthe like.

Examples of red pigments include red oxide, cadmium red, diachylon,mercury sulfide, cadmium, permanent red 4R, lithol red, pyrazolone red,watching red, calcium salt, lake red D, brilliant carmine 6B, eosinlake, rhodamine lake B, alizarin lake, brilliant carmine 3B, C.I.pigment red 2 and the like.

Examples of yellow pigments include chrome yellow, zinc chromate,cadmium yellow, yellow iron oxide, mineral first yellow, nickel titaniumyellow, navel orange yellow, naphthol yellow S, hansa yellow G, hansayellow 10G, benzidine yellow G, benzidine yellow GR, quinoline yellowlake, permanent yellow NCG, tartrazinelake, C.I. pigment yellow 12 andthe like.

Examples of green pigments include chrome green, chromium oxide, pigmentgreen B, C.I. pigment green 7,Malachite green lake, final yellow green Gand the like.

Examples of orange pigments include red chrome yellow, molybdenumorange, permanent orange GTR, pyrazolone orange, Balkan orange,Indanthrene brilliant orange RK, benzidine orange G, Indanthrenebrilliant orange GK, C.I. pigment orange 31 and the like.

Examples of purple pigments include manganese purple, first violet B,methyl violet lake and the like.

Examples of white pigments include zinc oxide, titanium oxide, antimonywhite, zinc sulphide and the like.

Examples of extenders include baryta powder, barium carbonate, clay,silica, white carbon, talc, alumina white and the like. Furthermore,there are Nigrosine, Methylene Blue, rose bengal, quinoline yellow, andultramarine blue as various dyes such as basic dye, acidic dye,dispersion dye, direct dye, etc.

Examples of inorganic additives include titanium oxide, zinc oxide, zincsulphide, antimony oxide, calcium carbonate, pearl white, talc, silica,calcium silicate, alumina white, cadmium yellow, cadmium red, cadmiumorange, titanium yellow, Berlin blue, Armenian blue, cobalt blue, cobaltgreen, cobalt violet, ion oxide, carbon black, manganese ferrite black,cobalt ferrite black, copper powder, aluminum powder and the like.

Inorganic additives among these coloring agents may be used alone or incombination with two or more kinds thereof. Particularly, carbon blackis preferable as the black coloring agent, and titanium oxide ispreferable as the white coloring agent.

Moreover, it is preferable to use particles according to the presentinvention, whose average particle diameter d(0.5) ranges between 0.1 to20 μm and which are even. If the average particle. diameter d(0.5)exceeds this range, the image sharpness is sometimes deteriorated, and,if the average particle diameter is smaller than this range, anagglutination force between the particles becomes too large to preventthe movement of the particles.

Further, in the present invention as for the particle diameterdistribution, the particle diameter distribution Span, which is definedby the following formula, is less than 5 preferably less than 3:Span=(d(0.9)−d(0.1))/d(0.5)(here, d(0.5) means a value of the particle diameter expressed by μmwherein an amount of the particles having the particle size larger thanor smaller than this value is 50%, d(0.1) means a value of the particlediameter expressed by μm wherein an amount of the particles having theparticle size smaller than this value is 10%, and d(0.9) means a valueof the particle size expressed by μm wherein an amount of the particleshaving the particle size smaller than this value is 90%).

When the Span is set to no more than 5, each particle has similarparticle diameter to perform an even particle movement.

Furthermore, as for a correlation between each particles, it is crucialto set a ratio of d(0.5) of the particles having smallest diameter withrespect to d(0.5) of the particles having largest diameter to not morethan 50 preferably not more than 10. Even if the particle diameterdistribution Span is made smaller, the particles having different chargeproperties with each other are moved in the opposite direction.Therefore, it is preferred that the particle diameters are formedclosely with each other and equivalent amounts of the particles areeasily moved in the opposite direction. To this end, the above range isobtained.

Here, the particle diameter distribution and the particle diametermentioned above can be measured by means of a laserdiffraction/scattering method. When a laser light is incident upon theparticles to be measured, a light intensity distribution pattern due toa diffraction/scattering light occurs spatially. This light intensitydistribution pattern corresponds to the particle diameter, and thus itis possible to measure the particle diameter and the particle diameterdistribution.

In the present invention, the particle diameter and the particlediameter distribution are obtained by a volume standard distribution.Specifically, the particle diameter and the particle diameterdistribution can be measured by means of a measuring apparatusMastersizer 2000 (Malvern Instruments Ltd.) wherein the particlessetting in a nitrogen gas flow are calculated by an installed analysissoftware (which is based on a volume standard distribution due to Mie'stheory).

A charge amount of the display media properly depends upon the measuringcondition. However, it has been found that the charge amount of thedisplay media in the information display panel substantially dependsupon an initial charge amount, a contact with respect to the partitionwalls, a contact with respect to the substrates, a charge decay due toan elapsed time, and specifically a saturation value of the particlesfor the display media during a charge behavior is a main factor.

After various investigations by the inventors, it is found that anadequate range of the charged values of each particles can be estimatedby performing a blow-off method utilizing the same carrier particles soas to measure the charge amount of the particles.

Then, the liquid powders used as the display in the information displaydevice according to the present invention will be explained. Theapplicant has the right of the name of the liquid powders utilized inthe information display device of the present invention as “electricliquid powders (trade mark)”.

In the present invention, a term “liquid powders” means an intermediatematerial having both of liquid properties and particle properties andexhibiting a self-fluidity without utilizing gas force and liquid force.For example, a liquid crystal is defined as an intermediate phasebetween a liquid and a solid, and has a fluidity showing a liquidcharacteristic and an anisotropy (optical property) showing a solidcharacteristic (Heibonsha Ltd.: encyclopedia). On the other hand, adefinition of the particle is a material having a finite mass even if itis vanishingly small and receives an attraction of gravity (Maruzen Co.,Ltd.: physics subject-book). Here, even in the particles, there arespecial states such as gas-solid fluidized body and liquid-solidfluidized body. If a gas is flown from a bottom plate to the particles,an upper force is acted with respect to the particles in response to agas speed. In this case, the gas-solid fluidized body means a state thatis easily fluidized when the upper force is balanced with the gravity.In the same manner, the liquid-solid fluidized body means a state thatis fluidized by a liquid. (Heibonsha Ltd.: encyclopedia) In the presentinvention, it is found that the intermediate material having both offluid properties and solid properties and exhibiting a self-fluiditywithout utilizing gas force and liquid force can be producedspecifically, and this is defined as the liquid powders.

That is, as is the same as the definition of the liquid crystal(intermediate phase between a liquid and a solid), the liquid powderaccording to the invention is a material showing the intermediate statehaving both of liquid properties and particle properties, which isextremely difficult to receive an influence of the gravity showing theparticle properties mentioned above and indicates a high fluidity. Sucha material can be obtained in an aerosol state i.e. in a dispersionsystem wherein a solid-like or a liquid-like material is floating in arelatively stable manner as a dispersant in a gas, and thus, in theinformation display panel according to the invention, a solid materialis used as a dispersant.

In the information display panel which is a target of the presentinvention, the liquid powders composed of a solid material stablyfloating as a dispersant in a gas and exhibiting a high fluidity in anaerosol state are sealed between two opposed substrates, at least onesubstrate being transparent. Such liquid powders can be made to moveeasily and stably by means of Coulomb's force and so on generated byapplying a low voltage.

As mentioned above, the liquid powders according to the presentinvention means an intermediate material having both of liquidproperties and particle properties and exhibiting a self-fluiditywithout utilizing gas force and liquid force. Such liquid powders becomeparticularly an aerosol state. In the information display panelaccording to the invention, the liquid powders are used in a state suchthat a solid material is relatively stably floating as a dispersant in agas.

As the aerosol state, it is preferred that an apparent volume in amaximum floating state is two times or more, more preferably 2.5 timesor more, and most preferably three times or more than that in nonefloating state. In this case, an upper limit is not defined, but it ispreferred that an apparent volume is 12 times or less than that in nonefloating state.

If the apparent volume in the maximum floating state is less than twotimes than that in none floating state, a display controlling may becomedifficult. On the other hand, if the apparent volume in the maximumfloating state is more than 12 times, a handling inconvenience during aliquid powders filling operation into the device such as a particleover-scattering may occur. The apparent volume in the maximum floatingstate is measured as follows. That is, it is measured by filling theliquid powders in a transparent closed vessel through which the liquidpowders are seen; vibrating or dropping the vessel itself to obtain amaximum floating state; and measuring an apparent volume at that timefrom outside of the vessel. Specifically, the liquid powders having avolume ⅕ of the vessel in none floating state are filled in a vesselhaving a average particle diameter (inner diameter) of 6 cm and a heightof 10 cm with a polypropylene cap (product name I-boy produced by As-oneCo., Ltd.), the vessel is set in the vibrator, and a vibration wherein adistance of 6 cm is repeated at a speed of 3 reciprocating/sec. isperformed for 3 hours. Then, the apparent volume in the maximum floatingstate is obtained from an apparent volume just after a vibration stop.

Moreover, in the information display panel according to the invention,it is preferred that a time change of the apparent volume of the liquidpowders satisfies the following formula:V₁₀/V₅>0.8;here, V₅ indicates the apparent volume (cm³) of the liquid powders after5 minutes from the maximum floating state; and V₁₀ indicates theapparent volume (cm³) of the liquid powders after 10 minutes from themaximum floating state. In this case, in the information display deviceaccording to the invention, it is preferred that the time change V₁₀/V₅of the apparent volume of the liquid powders is larger than 0.85, morepreferably larger than 0.9. If the time change V₁₀/V₅ is not larger than0.8, the liquid powders are substantially equal to normal particles, andthus it is not possible to maintain a fast response and effect ofdurability according to the invention.

Moreover, the average particle diameter d(0.5) (d(0.5)) of the particlematerials constituting the liquid powders is preferably 0.1-20 μm, morepreferably 0.5-15 μm, most preferably 0.9-8 μm. If the average particlediameter d(0.5) is less than 0.1 μm, a display controlling may becomedifficult. On the other hand, if the average particle diameter d(0.5) islarger than 20 μm, sharpness of the image display may be degraded. Theaverage particle diameter d(0.5) (d(0.5)) of the particle materialsconstituting the liquid powders is equal to d(0.5) in the followingparticle diameter distribution Span.

The particle diameter distribution Span of the particle materialconstituting the liquid powders, which is defined by the followingformula, is preferably less than 5, more preferably less than 3:Particle diameter distribution Span=(d(0.9)−d(0.1))/d(0.5);here, d(0.5) means a value of the particle diameter expressed by Amwherein an amount of the particle material constituting the liquidpowders having the particle diameter larger than this value is 50% andan amount of the particle material constituting the liquid powdershaving the particle diameter expressed by μm wherein an amount of theparticle material constituting the liquid powders having a particlediameter smaller than this value is 10%, and d(0.9) means a value of theparticle diameter expressed by μm wherein an amount of the particlematerial constituting the liquid powders having the particle diametersmaller than this value is 90%.

When the particle diameter distribution Span of the particle materialsconstituting the liquid powders is set to no more than 5, each liquidparticle has similar particle diameter to perform an even liquidparticle movement.

Here, the particle diameter distribution and the particle diametermentioned above can be measured by means of a laserdiffraction/scattering method. When a laser light is incident upon theliquid particles to be measured, a light intensity distribution patterndue to a diffraction/scattering light occurs spatially. This lightintensity distribution pattern corresponds to the particle diameter, andthus it is possible to measure the particle diameter and the particlediameter distribution. The particle diameter and the particle diameterdistribution are obtained by a volume standard distribution.Specifically, the particle diameter and the particle diameterdistribution can be measured by means of a measuring apparatusMastersizer 2000 (Malvern Instruments Ltd.) wherein the particlessetting in a nitrogen gas flow are calculated by an installed analysissoftware (which is based on a volume standard distribution due to Mie'stheory).

The liquid powders may be formed by mixing/grinding necessary resin,charge control agent, coloring agent, other additives, by polymerizingfrom monomer or by coating a known particle with resin, charge controlagent, coloring agent, and other additives. Hereinafter, typicalexamples of resin, charge control agent, coloring agent, other additivesconstituting the liquid powders will be explained.

Examples of the resin include urethane resin, acrylic resin, polyesterresin, acrylic urethane resin, silicone resin, nylon resin, epoxy resin,styrene resin, butyral resin, vinylidene chloride resin, melamine resin,phenolic resin, fluorocarbon polymers and the like. It is also possibleto combine two or more resins. For the purpose of controlling theadherence to the substrate, acryl urethane resin, acryl urethanesilicone resin, acryl urethane fluorocarbon polymers, urethane resin andfluorocarbon polymers are preferred.

Examples of the charge control agent include positive charge controlagents such as the fourth grade ammonium salt compound, nigrosine dye,triphenylmethane compound, imidazole derivatives, and so on, andnegative charge control agents such as metal containing azo dye,salicylic acid metal complex, nitroimidazole derivative and so on.

As for a coloring agent, various kinds of organic or inorganic pigmentsor dye with various colors as described below are usable.

Examples of black pigments include carbon black, copper oxide, manganesedioxide, aniline black, activate carbon and the like.

Examples of blue pigments include C.I. pigment blue 15:3, C.I. pigmentblue 15, Berlin blue, cobalt blue, alkali blue lake, Victoria blue lake,phthalocyanine blue, metal-free phthalocyanine blue, partiallychlorinated phthalocyanine blue, first sky blue, Indanthrene blue BC andthe like.

Examples of red pigments include red oxide, cadmium red, diachylon,mercury sulfide, cadmium, permanent red 4R, lithol red, pyrazolone red,watching red, calcium salt, lake red D, brilliant carmine 6B, eosinlake, rhodamine lake B, alizarin lake, brilliant carmine 3B, C.I.pigment red 2 and the like.

Examples of yellow pigments include chrome yellow, zinc chromate,cadmium yellow, yellow iron oxide, mineral first yellow, nickel titaniumyellow, navel orange yellow, naphthol yellow S, hansa yellow G, hansayellow 10G, benzidine yellow G, benzidine yellow GR, quinoline yellowlake, permanent yellow NCG, tartrazinelake, C.I. pigment yellow 12 andthe like.

Examples of green pigments include chrome green, chromium oxide, pigmentgreen B, C.I. pigment green 7,Malachite green lake, final yellow green Gand the like.

Examples of orange pigments include red chrome yellow, molybdenumorange, permanent orange GTR, pyrazolone orange, Balkan orange,Indanthrene brilliant orange RK, benzidine orange G, Indanthrenebrilliant orange GK, C.I. pigment orange 31 and the like.

Examples of purple pigments include manganese purple, first violet B,methyl violet lake and the like.

Examples of white pigments include zinc oxide, titanium oxide, antimonywhite, zinc sulphide and the like.

Examples of extenders include baryta powder, barium carbonate, clay,silica, white carbon, talc, alumina white and the like. Furthermore,there are Nigrosine, Methylene Blue, rose bengal, quinoline yellow, andultramarine blue as various dyes such as basic dye, acidic dye,dispersion dye, direct dye, etc.

Examples of inorganic additives include titanium oxide, zinc oxide, zincsulphide, antimony oxide, calcium carbonate, pearl white, talc, silica,calcium silicate, alumina white, cadmium yellow, cadmium red, cadmiumorange, titanium yellow, Berlin blue, Armenian blue, cobalt blue, cobaltgreen, cobalt violet, ion oxide, carbon black, manganese ferrite black,cobalt ferrite black, copper powder, aluminum powder and the like.

-   -   Inorganic additives among these coloring agents may be used        alone or in combination with two or more kinds thereof.        Particularly, carbon black is preferable as the black coloring        agent, and titanium oxide is preferable as the white coloring        agent.

Further, in the present invention, it is important to control a gassurrounding the display media (particles or liquid powders) in a gapbetween the substrates, and a suitable gas control contributes animprovement of display stability. Specifically, it is important to setthe relative humidity of the gas in the gap not more than 60% RH at 25°C., preferably not more than 50% RH, more preferably not more than 35%RH.

The above gap means a gas portion surrounding the display media obtainedby substituting occupied portions of the electrodes 5, 6 (in the case ofarranging the electrodes inside the substrates), the display media(particles or liquid powders) 3 and the partition walls 4 (in the caseof arranging the partition wall) and a seal portion of the informationdisplay panel from the space between the opposed substrates 1 and 2shown in FIGS. 1 a and 1 b.

A kind of the gap gas is not limited as long as it has the humiditymentioned above, but it is preferred to use dry air, dry nitrogen gas,dry argon gas, dry helium gas, dry carbon dioxide gas, dry methane gasand so on. It is necessary to seal this gas in the information displaypanel so as to maintain the humidity mentioned above. For example, it isimportant to perform the operations of filling the particles or liquidpowders and assembling the information display panel under an atmospherehaving a predetermined humidity and to apply a seal member and a sealmethod for preventing a humidity inclusion from outside.

In the information display panel according to the invention, an gapbetween the substrates may be adjusted so that the display media can bemoved to maintain the contrast. The gap is adjusted normally to 10-500μm, preferably 10-200 μm.

The volume occupied rate of the display media in a space between theopposed substrates is preferably 5-70%, more preferably 5-60%. If thevolume occupied rate of the display media exceeds 70%, the display mediamay become difficult to move, and if it is less than 5%, a sufficientcontrast cannot be obtained and a sharp image display is not performed.

EMBODIMENTS

Hereinafter, examples according to the first to third inventions of thepresent invention are shown so as to be explained further specifically.However, the present invention is not limited to the following examples.

Embodiment 1

Drive circuits of the information display devices whose drivingprinciple is shown in FIGS. 4 d and 4 e were produced. In this case,“inexpensive driver ICs with normal C-MOS output stage structure,capable of outputting two values of 0V and driving voltage (5V)” wereused instead of “expensive driver ICs having a function of outputtingtwo kinds of voltage”.

According to the information display devices of the embodiment 1, bycontriving the applied voltage waveform to either of rows or columns,the most inexpensive driver IC with C-MOS output stage capable ofoutputting only two values of 0V and the driving voltage was used toenable passive matrix drive so that cost reduction of the drive circuitcould be attained, which leads to cost reduction of the informationdisplay device.

Embodiment 2

A drive circuit of the information display device shown in FIG. 7 wasproduced. The drive circuit of embodiment 2 consisted of a row drivecircuit 11 and a column drive circuit 12, the row drive circuit 11consisted of a digital circuit 11 a and an analog circuit 11 b, and thecolumn drive circuit 12 consisted of a digital circuit 12 a and ananalog circuit 12 b. It was arranged that communication was transferredrespectively from the digital circuit 11 a to the analog circuit 11 band from the digital circuit 12 a to the analog circuit 12 b bydifferential signals, therefore, each ground levels could be setseparately. The digital circuits 11 a and 12 a had GND output terminalsof digital ground for common connection. The analog circuit 11 b had aVpanel output terminal of a panel driving power source −1 and a GNDoutput terminal of an analog ground −1, while the analog circuit 12 bhad a Vpanel output terminal of a panel driving power source −2 and aGND output terminal of an analog ground −2. The digital ground, thepanel driving power sources −1 and −2, the analog grounds −1 and −2shown in the figure could be independently set.

In the drive circuit of embodiment 2 mentioned above, as shown in FIG. 8a, the row drive circuit 11 applied the voltage of +V between the paneldriving power source −1 and the analog ground −1 to the informationdisplay panel while the column drive circuit 12 applied the voltage of−V between the panel driving power source −2 and the analog ground −2 tothe information display panel. Alternatively, as shown in FIG. 8 b, therow drive circuit 11 applied the voltage of −V between the panel drivingpower source −1 and the analog ground −1 to the information displaypanel while the column drive circuit 12 applied the voltage of +Vbetween the panel driving power source −2 and the analog ground −2 tothe information display panel. In this way, the digital circuit andanalog circuit (output circuit) were configured as differential drive sothat the ground level of the analog circuit could be arbitrarily setwithin the withstand voltage of the driver IC. As shown in FIGS. 8 a and8 b, each row and column is used with polarity in order to configure adrive circuit capable of handling two times withstand voltage. In otherword, it is possible to drive with high withstand voltage by means of aninexpensive drive IC with low withstand voltage. In addition, as shownin FIG. 8 c “a driver IC capable of outputting only two values includingground level (0V)” is used to configure a drive circuit for driving aninformation display panel by means of ⅓ bias with little influence ofcrosstalk.

According to the information display device of embodiment 2, a drivecircuit of the configuration in FIG. 9, in which ground level of theanalog circuit could be set independent of ground level of the digitalcircuit, was used so that the ground level of the analog circuit couldbe separated from the ground level of the digital circuit and a drivecircuit capable of polarity output could be configured by means of adrive IC with C-MOS output stage of unipolarity output. Therefore, “aninexpensive driver IC with general C-MOS output stage structure with lowwithstand voltage” can be used instead of “an expensive driver ICcapable of outputting both driving voltage and intermediate voltage” toachieve cost reduction of the drive circuit and therefore cost reductionof the information display device.

It is preferable that the row and column drive circuits of the drivecircuit of the information display device according to theabove-mentioned embodiment 2 are configured by drive ICs of triple-wellstructure for further cost reduction.

Embodiment 3

A drive circuit of the information display device shown in FIG. 9 wasproduced. In the drive circuit of embodiment 3 floating circuits 13-1and 13-2, in which GND of the digital and analog circuits were common(connected inside), were added before the row and column drive circuits11 and 12 of the drive circuit. In this way the floating circuits wereprovided separately so that the drive circuit could be configured byemploying every kinds of drive IC.

According to the information display device of embodiment 3, the driveIC provided with floating circuits was used so that the ground level ofthe analog circuit could be separated from the ground level of thedigital circuit and a drive circuit capable of polarity output could beconfigured by means of a drive IC with C-MOS output stage of unipolarityoutput. Therefore, cost reduction of the drive circuit becomes possible,which leads to cost reduction of the information display device.

INDUSTRIALLY APPLICABILITY

The information display device according to the invention is preferablyapplicable to the display unit for mobile equipment such as notebookpersonal computers, PDAs, cellular phones, handy terminals and so on; tothe electric paper such as electric books, electric newspapers and soon; to the bulletin boards such as signboards, posters, blackboards andso on; to the image display unit for electric calculator, home electricapplication products, auto supplies and so on; to the card display unitsuch as point cards, IC cards and so on; and to the display unit forelectric advertisements, electric POPs, electric price tags, electricshelf tags, electric musical score, RF-ID device and so on.

1. A method for driving an information display device, wherein displaymedia are sealed between two opposed substrates, at least one of whichis transparent, and wherein the display media, to which an electrostaticfield is applied, are made to move so as to display information such asan image or the like, characterized in that electrodes of theinformation display device are connected to predetermined potential in adriving voltage range with low impedance while an information refresh(scan) operation is not performed.
 2. The method for driving aninformation display device according to claim 1, characterized in that acircuit for connecting electrodes to predetermined potential in adriving voltage range with low impedance is configured to functionwithout power supply (in power-off state).
 3. The method for driving aninformation display device according to claim 2, characterized in thatelectrodes are connected to GND potential with low impedance so that abody diode at source-to-drain in output stage C-MOS structure of adriver is used and panel driving power source is set to GND level inpower-off state.
 4. An information display device characterized in thatthe information display device is driven by mean of the method fordriving the information display device set forth in one of claims 1 to3.
 5. A method for driving an information display device, in which aparticle movement type information display device is driven by passivematrix drive and dynamic drive, characterized in that the particlemovement type information display device is driven by means of a drivecircuit having an output stage equivalent circuit capable of outputtingonly two values of a predetermined driving voltage value and groundlevel.
 6. The method for driving an information display device accordingto claim 5, characterized in that the drive circuit comprises a driveintegrated circuit of triple-well structure.
 7. The method for drivingan information display device according to claim 5, characterized inthat the drive circuit comprises a floating circuit.
 8. An informationdisplay device characterized in that the particle movement typeinformation display device of passive matrix drive and dynamic drive isdriven by means of the method for driving the information display deviceset forth in one of claims 1 to
 7. 9. (canceled)
 10. (canceled)